Scott Jurek running through Central Park. Jurek says he can break the American road record for a 24-hour period, 162 miles, held by Mark
Godale.

I went running with Scott Jurek on a clear, chilly morning last month, an easy four-mile loop in Central Park. He ran another few miles with 50 or so adoring fans, then another few by himself, for a total of about 15. After that he showered and came to my house to cook lunch before going for a late-afternoon jog of another 10 miles or so.

That’s an easy day for Jurek, 36, an accomplished ultramarathoner. But one might say he has been in a slump: he has not won a major race since the 2008 Spartathlon. On the other hand, he set a personal record there, it was his third consecutive victory on the 153-mile course between Athens and Sparta, and he holds the fifth-, sixth- and eighth-fastest times in race history.

If last year was a wash, this year he is fit and psyched for the 24-Hour Run world championship in Brive-la-Gaillarde, France, on Thursday and Friday. It is a grueling race to determine how many miles runners can complete on a 1.4-kilometer road loop (about nine-tenths of a mile) in a 24-hour period.

Jurek says he can break the American record, 162 miles, held by Mark Godale. (The world record, 178 miles, and just about every ultramarathoning record from 100 to 1,000 miles, and from 24 hours to 10 days, are, Jurek said, “unassailably” held by Yiannis Kouros of Greece, who no longer competes.)

To win Brive, Jurek said, he must: “Get on it, crank around it, and get it done. It’s all in a day’s work.”

It’s a long day, and one that raises a particular aspect of Jurek’s training that makes him an especially interesting athlete: he is a vegan, consuming no animal products.

There are other professional athletes who do not eat meat: Milwaukee Brewers first baseman Prince Fielder, a vegetarian, may be the best known, and the hockey player Georges Laraque is also a vegan. But it is difficult for some to comprehend how this lifestyle is compatible with training weeks of 140 miles and more, “easy” runs of 40 miles and interval training that includes uphill three-mile repeats, all culminating in races that are often 100 miles or more, sometimes through deserts or frozen wastelands or up and down mountains.

Jurek certainly looks healthy enough. He is tall, dwarfing most competitive marathoners, not rail thin, with a quick smile and boundless energy. A few hours after our morning run, he showed up at my house and began pulling things out of the refrigerator and pantry with abandon: vegetables, greens, herbs, miso, tofu, olives, shallots, lemons, nut butter and more.

He displayed knife skills and good culinary judgment, preparing a meal for me and his girlfriend, Jenny Uehisa, a designer for Patagonia (he is sponsored by Brooks Sports). We ate a Greek salad with cucumbers, tomatoes, loads of olives and seaweed; a stir-fry of vegetables with tofu and a miso and cashew sauce; and a mound of quinoa.

Where did he learn to cook this way? And more to the point, how does he survive? After all, I said to him, none of my running buddies, a group of nonelite but defiantly dedicated marathoners who train in Central Park, maintain as rigorous a schedule as his, and many claim to have trouble consuming enough calories even while being omnivorous.

“The whole issue,” he said, “is exactly that: getting enough calories. The first thing to worry about isn’t so much what you eat, but how much you eat. You have to take the time to sit at the table and make sure your calorie count is high enough. And when you’re a vegan, to increase your calories as you increase training you need more food. This isn’t an elimination diet but an inclusion diet.”

Jurek grew up in Proctor, Minn., eating cookie dough, canned vegetables and his share of fast food. When his mother, Lynn, developed multiple sclerosis (she died this spring), he and his siblings began cooking, but the food was, he said, “very Midwest — meat and potatoes.” In college, his diet began to improve, and as he “saw how much disease is lifestyle related,” he began eating “real food, eating the way people have been eating for thousands of years.”

He made the transition to less meat and more fish, then eventually knocked out dairy and other animal products entirely.

“It’s really a mental barrier,” he said, and he obviously has experience overcoming those. He said he needed 5,000 to 8,000 calories a day, “and I get that all from plant sources. It’s not hard, either. I like to eat, and I don’t have to worry about weight management. All I need is a high-carbohydrate diet with enough protein and fat.”

He said he spent a great deal of time shopping, preparing and cooking food — and chewing. He is among the slowest and most deliberate eaters I know, and there is something about his determination at the table that is reminiscent of his determination on the road: he just doesn’t stop.